Control mechanism for hot-blast stoves



July 8 1930. F. R. M GEE CONTROL MECHANISM FOR HOT BLAST STOVES Filed Oct. 13, 1928 4 Sheets-Sheet .=:July s, 1930. F. R. M GEE ,7

I CONTROL MECHANISM FOR HOT BLAST STOVES Filed Oct. 15, 1928 4 Sheets-Sheet 2 5w H. NPR v .w X1 w n inik r m Q ,w W w 11v an a, Q n a. M M fi 0 Kim 5 O N M e Q m z 0 E R Q 3% Q NH- h M p Q h k Jr Jaw A July 8, 1930. R. MCGEE v CONTROL MECHANISM FOR HOT BLAST STOVES I Filed Oct. 15, 1928 4 Sheets-Sheet 3 July 8, 1930.

F. R. M GEE CONTROL MECHANISM FOR HOT BLAST STOVES Filed Oct. 15, 1928 4 Sheets-Sheet 4 1 I STANDARD AUTOMATIC STANDARD RECORDER CONTROL- CONTEOLLER PANEL. w

LIMIT SWITCH All Mentor.-

" ss n .1930 l 7 j 1 ,77t ,27?Z

v 3 FRANK n. MCGEE, or srhuBnnvrnnnomd. A

' oonrrnonivincnsnism son nor-:ntiesrsrovns V Application filed flctober 13, 1923. Serial 'No.312,293. V

lhis invention relates to hot blast stoves to close saidchamber from said burner when and; while not limited thereto, relates more the-stove is on blast. d particularly to a novel valve control for said A stack conduit '15 leadsfrom the lower stoves, and has for'one of its objects the pro end of-the stove to a chimney valve casing 5 visionjof a novel control mechanism which 16 which has a conduit 17 leadingtherefrom 5'5 will insure the .propersequencke of operation to a stack. ;A cold blast conduit 18 isconofthe valves of said stoves. I nected withand extends into the casing 16 Another object is to provide a novel valve adjacent its lower end and is adapted to de control mechanism for stoves of this class liver cold 'airunder pressure to the stove.

v which will be automatically operated to shut A valve .19 is provided to control the flow of 60 combustion chamber and isprovided. with a have their adjacent endsthreaded into the off the fuel supply, close the chimney valve, air through the conduit 18. A stack or chimand when air to supportcombustion is supney valve 20 is mounted for vertical moveplied to the stove by a fan, will stop said fan ment in the casing 16 and is adapted to seat in the proper j sequence when the stove has against a seat 21to close the path to the stack reached a predetermined temperature. conduit 17 when inits uppermost position; 65 A'further object is to provide an automatic and .to rest on a support 22 on the cold; blast safety control for closing the fuel valve in conduit '18 when in its lowermost or open pocase the fan operating motor should become sition. v deenergized for any reason. A valve rod 23 is connected to the chimney .20 In the drawings: I 1 valve and extends vertically/through the 70 Figure 1 is a sectional side elevation of a valve .casing16. A yoke member 21 is slid- 1 stove having my -invention applied thereto. .ably. mounted on the rod 23 and isadapted to Figure 2 is a side elevation taken at right engage a collar 25. Apairof cables 26 have angles to Figure 1. 1 their lower ends secured to the oppositeends Figure 3 is an enlarged fragmentary view of the'yoke 2A and their'upper ends secured 75 of the gas control mechanism. to drums27 of a hand operated hoisting ap- Figure l. is a view taken on the line lV-IV paratus 28, so that the valve 20 may bemanof Figure 2. d V A ually operated, if desired. Figure 5 is a schematic wiring diagram The gas valve?) is provided with a crank- .30 showing the control circuits. I I V shaped operating arm 29 which is mounted .80 Referring more particularly to the drawon a shaft 30 journaled in the valve casing ingsfthe letter A designates the hot blast 9*, which shaftis provided with an operating stove as a whole, which is of single passcon lever 31. A pair of link members 32 and 33, struction and comprises a cylindrical checkhaving a turn-buckle adjustment 34, are pro- 35 er-chamber 2 and a separate outsidecombusvided for, operating the valve v9 hyhand. tion chamber 3' which is connected to the up- The upper link member 32 has a loose coner end of the checker chamber 2 by. a coninection with the lever 31, as at 35-, while the cal distributing chamber 4. A gaseous fuel lower, link member 33 has a pivotal mounting burner 5 is provided at the lower end of the on a fixed pivot 36fon a frame 37 and the linksgas inlet port 6 and van air inlet port "7. The turn-buckle 34, so that they may be drawn gas port-6 is connected by a conduit 7 to :1 toward and away-from-each other to operate supply. main '8, and a vertically swinging the valve. d I valve 9 is provided for controlling the flow In order to provide for the proper sequence .45 of gas through the conduit 7 to the burner 5. of operation of the valves 9 and-20 the"f0l- The air port 7 is connected by a conduit 10 lowing interlocked mechanical mechanism is with a fan 12 adapted to beoperated byan provided. 7 a 1 electric motor 13. A motor .40 is mounted ona stationary base A water cooled slidevalve 14: is provided ,andois adapted tooperate aZdrum-shaft 41 at thelower end of the combustion chamber 3 through a speed. reducing mechanism 42.

drum a3 is mounted on one end of the shaft ll. A cable A l has its one end anchored to the shaft ll and is trained over a sheave 45 mounted in a sheave-frame e16 suspended from one end of a cable'll'. The cable 44: extends down from the sheave 45 and is secured to the drum 43, so that as the drum 43 is rotated the cable 44 will be either wrapped on or unwrapped from the to the direction of rotation of the drum. The cable 47 is trained over an elevated sheave l8 and extends down and has its otherend secured to a counter-weight frame 4:9

' carr in a counter-wei ht 50. b D

link

ed to be normally into the path of travel of the weight 60, so as A sheave 51 is journaled in the counterweight i'rame 49 and a valve operating cable 52 is trained under the sheave 51 and has its one end extended up and over aseries of elevated sheaves 53 then down and secured to the valve rod 23 of the chimney valve 20. The other end of the cable 52 is extended up and over a series of elevated sheaves 54 and then downwardly and secured to one end of a rod The rod link 55 extends downwardly through the frame-work 37 and is connected to one end of a short length of cable 57 which extends downwardly and is trained under a sheave 58 journaled in a counter-weight frame 59 carryinga counteraveight 60. The cable 57 extends upwardly from the sheave 58 and is secured to the lever 31 which operates the shaft 30 and gas valve 9.

The counter-weight 60 extends into and is adapted to have a limited movement relative to a casing 61, r A swinging stop member 62 is mounted on the casing 61 and is adaptmoved into the casing 61 to stop said weight. A toggle mechanism 63 is'provided for holding the stop member 62 in position in the casing, and a weight operated tripping lever 65, having an attached weight 65, is provided for tripping or breaking the toggle and permitting the stop member 62 to swing out of operative posit-ion. A magnet 66 is provided for normally holding the tripping lever 65 in inoperative position.

A switch 67 is provided on the frame-work 37 and is adapted to be operated by a triplug 68 on the rodlink 55 to energize the fan motor 13.

A pilot light 70 is provided in the combustion chamber 3 to initially light the gas, and after the stove has been once heated this light may generally be extinguished since the brickwork of the stove will remain sutficiently hot to ignite the gases.

The operation of the apparatus so far described is as follows:

Assuming that the stove A is on air with the stack valve and gas valve closed, the motor 40 will be energized in the forwarddirection to wind up the cable 44 on the drum 43,

drum 43 according to open position on the rest 22. I After the chimney valve 20 has come to rest on the rest 22, the cable 52 will continue to be slacked and permit the opposite end to be lowered due to the pull of the weight 60. This "movement will cause the rod 55 to move downwardly so thatthe trip-lug 68 will trip the switch 67 and energize the fan motor 13 to force air for supporting combustion into the combustion chamber.

After the weight 60 has moved a predetermined distance it will engage the stop 62 and come to rest. The main weight 50 will still be moving upwardly so as to further relieve the tension on the cable 52 and, as this tension is relieved, the gas valve 9 will open to permit the gas to enter the burner 5 and be ignited by the pilot light 70.

A limitswitch is provided for stopping the operation of the motor 40 when the weight 50 has been lifted sufficiently to open both the stack and gas valves.

When the stove has been heated sui nciently and it is desired to put the stove on air, the

motor 40 will'be reversed so asto unwind the cable 44, and thereby lower the weight 50 which will pull or tension the cable 52. As the weight 50 is lowered and tension is applied to the cable 52, the gas valve 9, which is the lightest structure connected to said cable,

will be first raised to closed position, the

weight 60 will be next raised to its elevated position and permit the trip-lug 68 to operate and open the switch 67, so as to deenergize the fan motor 13. As the cable 44 is continued to be unwound and the weight 50 continues to drop and apply tension to the cable 52, the chimney valve 20, which is considerably heavier than the valve 9 and weight 60, will be closed.

In order to provide for automatically shutting oil the fuel after the stove has been brought to the desired temperature, and also to provide for the automatic cutting oil of the fuel supply in case the fan motor should be deenergized, I have provided the following mechanism, illustrated in the wiring diagram of Figure 5.

A thermo-couple is provided at a convenient location in the conduit 15 leading to the stack so as to be heated bythe stack or waste gases. The leads 76 and 77 from the thermo-couple 75 lead to a Standard Leeds and Northrup or other automatic recording controller 78, which is connected by leads 79 and 80 with a standard control panel 81.

Lines 82 and 83 lead from a source of current to the panel 81, and branch lines 84 and 85 are connected to the motors 40 and 13 by a hand operated switch 86 for comcircuit to the motor 13.

energized by pleting the circuit to the motor 40 the cable operated switch 67 for completing the Themagnet- 66 is in series with'the motor 13 so that ifthe motor 13 is deenergized the magnet 66 will also be'deene'rgized to drop the weight I The standard panel 81 is adapted to complete a reverse circuit tothe motor 40 through leads 8'? and 87 the current from r the thermo couple 75., Therefore, when the temperature of the stove has been raised to a' predetermined' amount,the panel 81 will be operatedto complete the reverse, current to the motor 40 and cause saidmotor to operate to valves and declose the gas and chimney energize the fan'motor 13. a 1 c t The details of the automatic recorded controller 7 8 and the control panel 81 have been entirely omitted, since these are standard pieces of electrlcal apparatus well known 1n the art and to illustrate and describe their details of construction would only serve to confuse and make obscure this invention.

While I have shown and described one specific embodiment of my invention I do not wish to be limited thereto, since various modifications may be made without departing from the scope of my invention, as defined in the appended claims.

I claim: V

1. The combinationwith a hot blast stove having chimney and fuel valves, of means for opening and closing said valves, said meansin'cluding a prime mover, connecting balanced against each other whereby said chimney valve due to its greater weight will open before said fuel valve and said fuel valve will close before'said chimney valve, and means for automatically setting said prime mover in operation to close said valves when the temperature of said stove has i reached a predetermined degree.

- 2. The combination with a hot blast stove having chimney and fuel valves, a fuel burner and a motor driven fan for supplying air to support combustion, of mechanical means .for openlng and closmgsaid valves,

said'means'including a .prime mover, a flexible connecting member between said prime mover and said valves, said connecting memher being trained over suitable sheaves and combined-with weights sothat said valves are balanced against each other whereby said 7 chimney valve due to its greater weight will open before said fuel valve and said fuel valve will close before said chimney valve,

and means operable by said flexible connecting member for energizingsaid motor driven fan priorto the opening of said fuel valve and for deenergizing sa1d motor driven fan after said fuel valve is closed.

said means including a prime mover,

when the panel is 'ber being trained over a flexible member between, said prime mover and said valves, said connecting mem- 'ber being so arranged that'said valves are matically setting said prime mover in oper- 3. The combinationwith ahot blast stove] having chimney and fuel valves, a 7 fuel burnerand a motor air to support combustion, means foropening'and closing sa1d valves,

driven fan for supplying V r, of mechanical I ible connecting member between said prime mover and said valves, said connecting memsultable combined with weights so that said valves are balanced against each other whereby said chimney valve due to'its greater weight will i 'open before. said fuel valve and said fuel f before said chimney valve, :I

valve will. close means operable by said flexible connecting member for energizing said motor driven fan prior to the opening of said fuel valve and for deenergizing said motordriven fan after sheaves andv said fuel valve'is closed, and mean sffor automatically closing said fuel valve if the-circuit to said fan motoris broken while said I a fuel valve is open.

4; The combination with ahot blast stove having chimney and fuel valves, a :fuel burner and a motor driven fan for supplying ,air to support combustion, of mechanical 5 means for opening and closing said valves, sa1d means including a pr1me mover, a flex ible connecting member between said pr me mover and said valves, said connecting memher being tra ned over suitable sheaves and f combined with weights sojthat said valves are balanced against each other whereby said chimney valve due to itsgreater weight will open before' said fuel valve and said fuel valvewill close before said chimney valve,

means operable by said flexible connecting member for energizing said'motor driven fan prior to the opening of said fuel valve and for deenergizing said motor driven fan after said fuel valve is closed, and means for autoation to close said valves when the temperature of said stove has 'reached'a predeter-e mined degree.

In testimony whereof, I have hereunto set I my hand.

FRANK R. MeGEE. 

